Tokyo Metro 7000 series
The 7000 series is a Japanese city commuter electric multiple unit. Built from 1974 to 1989 for the Teito Rapid Transit Authority (now known as Tokyo Metro), the 7000 series sets have been used on the Tokyo Metro Yūrakuchō Line since 1974 and the Tokyo Metro Fukutoshin Line since 2007, although their use is currently diminishing. History The 7000 series was conceived in 1974 as a train that would allow for easy maintenance, have the latest technology and have a long lifespan, in addition to being the first sets to operate on the then-soon-to-be-opened TRTA Yūrakuchō Line. The first set, three-car set 7101, was delivered some time in 1974 and entered service in October 1974; more sets were later built and put into service progressively. When the TRTA was dissolved in 2004, ownership of the sets was handed over to Tokyo Metro. In addition to being used on the Tokyo Metro Yūrakuchō and Fukutoshin lines, the sets are also used for through-running through to and from the Tobu Tōjō Line, Seibu Yūrakuchō and Ikebukuro Lines and the Minatomirai Line. With the introduction of the 10000 series sets in 2006, the age of the 7000 series sets began to show. Starting in 2010, a total of eight sets were transferred to the KRL Jabodetabek in Indonesia, where they see service today. As of 2018, the 7000 series sets are reaching the end of their service life; the company is planning to replace the 7000 series sets with the newer 17000 series sets by March 2023. Design The 7000 series use a fairly modern design for the time with an unpainted body made of an extruded aluminum alloy. The design of the sets is extremely similar to what is seen on the Tokyo Metro 6000 series sets. Specifications Construction is of an extruded aluminum alloy. End cars are 20 meters long, 2.8 meters wide and 4.145 meters high. The sets originally used a thyristor-chopper control system, with Mitsubishi and Hitachi providing the thyristor chopper systems; those produced a low drone when the train accelerated from idle. Starting in the 2000s, most older sets received "Type B" refurbishment; improvements included the addition of automatic station broadcasting systems, addition of wheelchair spaces and the changing of the roller blind-type destination indicators to three-color LED indicators among other improvements. Another notable improvement was the changing of the chopper control systems to variable frequency drives; the drives were manufactured by Mitsubishi or Hitachi in two- or three-level formats. All variable frequency drives supplied were insulated gate bipolar transistor-based drives. Two-level Hitachi drives at 165 kW produce a loud screeching noise, two-level Hitachi drives at 160 kW produce a subdued wailing noise, two-level Mitsubishi drives at 165 kW voltage produce a loud hissing sound and two-level Mitsubishi drives at 160 kW voltage produce a sharp hissing sound. The sets also had three-level drives, but those appear to have been removed; three-level Mitsubishi drives produce a unique cadence while three-level Hitachi drives produce a melodic sound. Newer sets received "Type C" refurbishment which was much smaller in scale, where work was done mainly to paintwork and interior work and modifications to body construction. References *Wikipedia.org Category:Electric Trainsets Category:Tokyo Metro trains Category:TRTA trains Category:Kawasaki locomotives Category:Kinki Sharyo locomotives Category:Nippon Sharyo locomotives Category:Tokyu Car locomotives